Poly V belt replacement

[roneg]

When I first lifted the belt cover (machine was in vertical position) the belt was so tight against the headstock the motor would not turn. It would try, then blow the circuit breaker at the home of the seller. I dis connected the main drive belt then turned on again. The motor seem to run fine at this point.

[JPG]

I gotta ask what the idler shaft looks like with the belt cover off. The vent plate pix looks like the bearing is sticking out the rear too far.

As for the eccentric/bearing moving 'into' the headstock, there is nothing to prevent that other than the control sheave etc.

The bearing inside the eccentric is positioned and retained by the set screw under the eccentric.

If the idler shaft pulley(idler sheave) is not positioned correctly the poly-v belt will not be positioned correctly relative to the drive sleeve pulley.

Both the eccentric and the bearing should be very close to flush with the surrounding part of the headstock.

I will add a link to some pix.
https://www.shopsmith.com/ss_forum/view ... 961#p40961

[roneg]

Thanks for the link JPG..very helpful.

Question; in dis-assembling the 510 I noticed the key falling out of the keyway soon as I removed the quadrant assembly, along with the control sheave.
What is supposed to keep it in? is this a typical key?

FWIW my machine has the split type eccentric bushing.

[JPG]

There is a 'spot' near the end of the keyway near the middle of the idler shaft. That spot deepens the slot. The key end is bent so as to drop into the spot. The idler sheave slips over that area and prevents the key from coming out. The idler sheave is positioned/retained on the idler shaft by a very small almost inaccessible 'hair clip' (for lack of a better name) that is shaped like the clip on the caster piston but is much smaller. The clip drops into a small groove in the shaft.

This is true with both versions of the idler shaft.

IF the idler sheave is not positioned correctly on the idler shaft, the resultant speed range is altered.

[roneg]

Thanks for confirming that for me JPG. Just waiting on belts before reassembly.

Ron

[roneg]

I gotta ask what the idler shaft looks like with the belt cover off. The vent plate pix looks like the bearing is sticking out the rear too far.

[JPG]

I gotta ask what the idler shaft looks like with the belt cover off. The vent plate pix looks like the bearing is sticking out the rear too far.

YEP THAT ain't right!!! THAT explains a lot of stuff re speed range.

Time for a complete disassembly and put together correctly. *

Is the set screw under the eccentric 'over' the notch in the bearing? I am guessing it is not.

Considering recent posts/questions, the PO got it pretty well screwed up.

WE WILL get it corrected!!! *

[roneg]

Yup..I agree. It is already disassembled. Well all that needs to be for the poly v belt replacement. Pretty sure mine gets the three notch placement. There is no set screw on mine, and belts came today. So I'm ready. Gotta figure that idler bearing goes flush. All the parts n bearings seem really good shape. Seems low mileage er I mean usage!

[JPG]

I just realized a thread describing reassembly of the idler shaft etc. might be useful!

Maybe some day I will do that.

[roneg]

You mean to tell me after all these years there isn't one? I'll post some pictures of my installed parts tomorrow. Just about ready to fire it up!